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A fully integrated broadband multi-state reflectometer (MSR) covering both 2- and 16-GHz bands is developed using microelectromechanical systems and monolithic-microwave integrated-circuit technology for complex permittivity measurement of biological material. The MSR consists of a dual-band phase-locked loop, a power amplifier, a directional coupler, an impedance tuner, two RF power detectors, and a micromachined silicon planar probe with an open-ended coaxial aperture. All the active and passive circuit components have been integrated on the micromachined probe platform in a small form factor of \ 6.8 mm\ \times \ \ 50 mm\times \ \ 0.6 mm. To cover a broad bandwidth ranging from 2 to 16 GHz, the circuit components have been designed with multi-octave characteristics. The performance of the fabricated reflectometer has been verified by comparing the measured permittivities of 0.9% saline, pork muscle, and pork fat with the reference data. To the best of our knowledge, this is the first demonstration of a miniaturized active integrated broadband reflectometer for complex permittivity measurement of biological material. [ABSTRACT FROM PUBLISHER]

Frequency switched transmit diversity (FSTD) is a simple diversity technique which can be easily combined with existing multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) schemes to support an increased number of transmit antennas. For the MIMO-OFDM based on FSTD, this letter proposes a reduction scheme of peak-to-average power ratio (PAPR). The proposed scheme generates signal candidates (SCs) by mapping the subparts of OFDM symbols onto multiple antennas under the criterion of reducing correlation among the SCs. The proposed scheme is shown to provide good PAPR performance and to allow a low-complexity detection of the transmitted SC without side information. [ABSTRACT FROM PUBLISHER]